Maybe there can be some other questions that enable to estimate the
level of experience working/administering with Linux. Like:
experience with LVM, NFS, RAID, work with partitions, work with Linux
installation server (like Coobbler), kickStart, etc.

Are there some user profiles that would describe the required test
participants? Stephanie's survey draft suggests that users (or one group
of them) should be linux sys-admins. I think that very important group
of test participants should include less experienced users (even linux
novices). These profiles could affect the content of the questionnaire.